Researchers Find Cat Allergy Response Trigger

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The latest news in allergy research is nothing for cat lovers to sneeze at.

Scientists at the University of Nottingham, England, have made a discovery that could change the world for allergy sufferers who have ever had to choose between their or a family member’s health and their beloved feline companion.

A team of immunologists at the university’s School of Molecular Medical Sciences, with funding from the charity Asthma UK, have identified a cell component which plays a key role in triggering allergic responses to cats.

Allergic reactions happen because in some people, exposure to ordinary substances in the environment such as pollen or cat dander causes an overreaction of the immune system. The perceived attack leads the body to produce a molecule called IgE, which eventually leads to release of further chemicals such as histamines, which cause an inflammatory response and the symptoms of allergy attacks — itchy eyes, sneezing, runny nose and wheezing.

The research results, recently published in the Journal of Biological Chemistry, has focused on the role of the mannose receptor (MR), a receptor found on the surface of immune cells known as dendritic cells. These cells are present in tissues exposed to the outside world such as the skin and the inner lining of the nose, lungs, stomach and intestines, and are therefore the first to come in contact with allergens.

In earlier research, the team had discovered that the MR binds to a wide range of allergens and is a central player in the allergic response to house dust mites. In their latest study they analyzed how the MR contributes to allergies caused by Fel d 1, a protein in cat saliva and skin glands. Most people who are allergic to cats are allergic to Fel d 1.

The scientists were able to prove that the body needs the MR in order to recognize Fel d 1 as a foreign invader and provoke an allergic reaction.

The development will come as a particular relief to people with asthma who tend to be the most strongly affected by allergic reactions to environmental factors such as house dust or cat saliva present in airborne dander.

“Many people with asthma are highly sensitive to airborne allergens such as cat dander or house dust mites,” said Dr. Amir Ghaem-Maghami, one of the researchers. “In fact many studies have shown that up to 40 percent of children with asthma are allergic to cat allergens.”

The incidence of allergies has increased sharply over the past few decades. The researchers say allergic asthma in children has reached epidemic proportions in many industrialized countries, including the UK.

“A better understanding of how the interaction between allergens and the immune system leads to allergy is vital if we are to develop more effective and efficient treatments” for both asthma and allergies, said Dr. Ghaem-Maghami.

Thanks to Dr. Ghaem-Maghami and this dedicated research team, people who thought they would never be able to have cats may soon be able to share their lives with a feline friend.